timo888 wrote:It may not be a matter of simply affording the cost...the prospective buyer might be one who chooses for the sake of the environment to consume less energy. Does it really make sense to heat 5 liters of water to make a 1.5 ounce beverage?

I purchased a two-group commercial for a friend who was going to open a shop, because it was immaculate other than a very short period of light use with little to no maintenance and cleaning. He bailed on the purchase (and the shop), and I had a hundred and seventy-five pound white elephant in my living room. Being a technician, I decided to clean up the thing. Amazingly, in one afternoon, it was spotless. Most of the problem was a thin veneer of neglect from the wannabe baristi that had operated it, and the fact that the owner didn't really have a coffee clue. Since the Mermaid was dumping used LM's on the open market faster than rat's deserting a sinking ship, and the entire used commercial machine market had been sullied by glue-factory-bound quality of most of the machines available, I couldn't generate any interest. Now I had a great, shiny, new looking two-group taking up space in my house. Well, being handy, and being a technician, I decided that the dishwasher wasn't being used, and there is plumbing and drainage going to waste, and I can find a 240V recept and plug anywhere (theatre friends...) and my drop is just on the other side of the wall from the kitchen...
Short story long, I plugged that thing in and let it rip. I keep in touch with the local machine repair gurus pull a handful of shots throughout the day, and hot water for tea, oatmeal, whatever, and that 1.5 oz drink turns into half a dozen drinks a day, at the very least.
Heating up 2 litres a half a dozen times a day or maintaining the 12 litres 24-7, it's almost a wash.
I'd trade the used commercial for a decent new single group, like the Alex Izzo, or something, in a minute, but Silvia has been forever relegated to the road.

Compass Coffee wrote: [ ... ]
EDITED (AFTER RE-READING LATER): Eric, I apologize if that came off as harsh and any feelings were hurt. Pulled a long 17hr double yesterday followed by short night's sleep but no excuse to be rude. Not trying to scare newer forum members away!

'salright. I'm trying to hold down a fulltime programming job and start an espresso shop w/o a loan and with Starbucks invading Lincoln -- I totally understand the exhaustion thing. My head is fried at the end of the day, then I plan until 1am and then can't sleep until 4am. Then I get to go be creative again.

Anyway, you're right about the duty cycle, which I forgot. I just posted something to get a zeroth iteration rolling. I really wish the manufacturers would post a rough measurement. It woudn't be perfect -- it couldn't be, but a range would be useful.

Say, to know that machine A needs X kWh to go from cold and empty to ready for a good shot. Then Y kW on average just to idle, and Z kW to pull shots continuously.

But as someone else pointed out, what home user need care? I don't think a commercial machine is needed for the daily god shot; it comes into its own if you need 20 of them *right now*.

Eric (who signed the lease today, and is now bracing for the nightmares about customers complaining because it's not JUST LIKE STARBUCKS)

Compass Coffee wrote:Pulled a long 17hr double yesterday...

That is long, I try to keep mine under 40 seconds.

Sorry, couldn't resist. In the words of the immortal Groucho: you can't expect them all to be good.

Yes, it filled the hot tub. (And could only pull it off with a direct plumbed machine. )

With respect, what you have just demonstrated is a method of finding the consumption by measuring. Yes, if you know the duty cycle of the heater you can calculate the consumption, but the duty cycle isn't usually specified, so you have to resort to measuring it (as you say above), then making an approximate calculation.

Surely it's just as easy to use a cheap power meter, if you have one, rather than using a stop watch and tediously deriving a less accurate power consumption.

Bill

I'd agree using timed duty cycle versus a Electricity Usage Monitor wouldn't be as precise. They may be cheap but if you'd been laid off they're an unnecessary luxury item with very limited practical use. Let's say if timed method yields ~$3 per month cost versus actual metered $3.23 would it really matter for discussion purposes? FWIW it wasn't really all that tedious IMO to time the duty cycle over a 15 minute idle period and extrapolate. Much less tedious than initially working out accurate temperature management flush technique.

Compass Coffee wrote:I'd agree using timed duty cycle versus a Electricity Usage Monitor wouldn't be as precise. They may be cheap but if you'd been laid off they're an unnecessary luxury item with very limited practical use. Let's say if timed method yields ~$3 per month cost versus actual metered $3.23 would it really matter for discussion purposes? FWIW it wasn't really all that tedious IMO to time the duty cycle over a 15 minute idle period and extrapolate. Much less tedious than initially working out accurate temperature management flush technique.

Yes, measuring the duty cycle is a perfectly reasonable way of getting an idea of the electrical consumption.

My nit pick is that this is just a different way of measuring the consumption of an actual machine. It doesn't let you calculate the consumption of a machine from its specifications, which was my original point.

In fact you could calculate the heat loss of a machine, and hence its approximate consumption if you know a few things about it. You need to know the operating temperature, the ambient temperature - both of which can be guessed reasonably well - the surface area of the boiler, the thermal resistance of the boiler and the thermal resistance of any insulation around the boiler. These latter factors are not going to be readily available to most people so calculation is not a useful of finding the consumption of a machine that you can't get your hands on!

Bill

Purchasing a commercial machine for home and worrying about electric is like buying a Ferrari and worrying about the cost of gas. It is the least expensive part of the equation. I have a two group Faema that I frame up rebuilt as a winter project. I learned a lot from the rebuild. I even ran a 30 amp 220v line and half inch water line just for it. I let it run 24/7 during the fall/winter/spring and did not notice any change in the electric bill. That machine has an 11 liter boiler which I did insulate.

Why use a commercial machine in the home, performance. You will not get the same shot/steam/recovery performance from a home machine. You can get close with a few of the high end home machines, but there is still a difference. In the end, I retired the two group to the basement and got an Elektra A3, which I still consider to be a commercial machine but in a single group. It still produces the best tasting espresso IMHO of any machine I have had the opportunity to try, short of a LM two group. I also insulated the boiler on it.

RapidCoffee wrote:Sorry, but I'm gonna disagree on most points. Other than items like grouphead gaskets, I'd expect commercial-grade equipment to last basically forever in a home setting.

Maybe it's a case of YMMV but on my LM I need to replace the boiler relief valve at least once a year for example. Parts like that age regardless of use. Heat is heat and pressure is pressure whether the machine is pulling coffee or sitting still if it's on all the time, as is recommended for commercial machines.

Darryl